Carton having gusseted side flaps

ABSTRACT

A carton and the method of folding the closure flaps for adhesive application and closing the carton. Gusset side flaps are first folded out and the major flap to which the side flaps are connected is folded in. This forms a virtual coplanar surface to which adhesive is applied. Next the gusset side flaps are folded in and under the major flap to which they are attached. The second major flap is then folded down over the first major flap. Two cut-score lines which operate in conjunction with a grip tab integrally connected to one side flap provide an easyopen feature which makes a triangular opening.

United States Patent Tessmer, Jr.

[451 May 9, 1972 [54] CARTON HAVING GUSSETED SIDE FLAPS [72] Inventor: Raymond G. Tessmer, Jr., Cincinnati,

2,565,182 8/1951 Maxon ..229/l7 3,079,063 2/1963 Yezek ...229/ l 7 3,185,374 5/1965 Feeney ..229/17 3,233,795 2/1966 Struble ..229/17 X 3,421,680 1/1969 Cohee ..229/ l 7 Primary Examiner-M. Henson Wood, .1 r. Assistant Examiner-Thomas C. Culp, .lr. Attorney-John V. German and Richard C. Witte 57 ABSTRACT A carton and the method of folding the closure flaps for adhesive application and closing the carton. Gusset side flaps are first folded out and the major flap to which the side flaps are connected is folded in. This forms a virtual coplanar surface to which adhesive is applied. Next the gusset side flaps are folded in and under the major flap to which they are attached. The second major flap is then folded down over the first major flap. Two cut-score lines which operate in conjunction with a grip tab integrally connected to one side flap provide an easyopen feature which makes a triangular opening.

4 Claims, 8 Drawing Figures PATEHTEMAY 9 I972 1 SHEET 2 BF 3 Fig.1. 3

Fig. 5 INVENTOR. Raymond G.Tessmer, Jr.

ATTORNEY m PATEMEBMAY 91972 51 321 FI'iEIFT 3 BF 3 INVENTOR.

Raymond G. Tessmer, Jr.

ATTORNEY FIELD OF THE INVENTION This invention relates to improvements in the art of packaging, more particularly to a carton and a method of closing the canon which is reliably performed at production speeds to make a siftproof carton having an easy-open feature. The carton of the present invention is particularly useful for packaging particulate, granular, or powdery products.

DESCRIPTION OF THE PRIOR ART The prior art shows several techniques used to overcome sifting. One technique is to attach ears, commonly known as Van Buren ears, to the ends of one of the major flaps and bond these cars to the carton side panels. The ears close a potential sift line and hold the flap down tight.

Another technique is to use gusset-type side flaps to eliminate an opening through which product previously could sift to provide a tighter mechanical seal due to more bulk at the sealing line. The gusset side flaps have been folded to three positions: between the two major flaps, on top of both major flaps, and down the outer surface of the side panel. Folding the side flaps either on top of the major flaps or down the side panel is unsightly, and folding the flaps between the major flaps required a Van Buren ear to pull the overlying major flap down tightly on the side flaps. Folding the side flaps between the major flaps also required additional material on the distal edge of the underlying major flap. The additional material is bound between the side flaps and the overlying flap, otherwise the underlying major flap is forced downwardly by the side flaps and the mechanical seal between the underlying flap and the panel it abuts is destroyed. It is believed that the gusseted side flaps were folded to those three locations in the prior art because of lack of an acceptable adhesive-applying technique to bond the outside surfaces of the gusset portions to each other.

The above-mentioned techniques have resulted in complex folding and bonding operations. Bonding is accomplished either by applying an adhesive to the relevant areas before forming the carton and later activating that adhesive or by applying adhesive immediately before the surfaces to be joined are brought into contact. The latter method generally requires applying adhesive in more than one plane.

OBJECTS OF THE INVENTION BRIEF SUMMARY OF INVENTION In accordance with one aspect of the present invention, a carton is equipped with gusset side flaps which underlie the two major closure flaps creating a neater looking, better sealed carton. Adhesive bonds are formed between the superposed gusset side flap parts and also between the two major closure flaps. If an easy-open pour spout feature is desired, this can be provided by the addition of two cut-score lines, one on a gusset side flap and one on a score line between the outer major closure flap and its adjacent panel.

In accordance with another aspect of the present invention there is provided a novel method of folding the closure flaps on the carton to allow adhesive to be applied in essentially a single, narrow plane. First the gusset side flaps are folded outwardly and the back flap folded inwardly, then adhesive is applied in a single narrow plane, and finally the gusset side flaps are folded inwardly under the back flap and the front flap is folded on top of the back flap.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:

FIG. 1 is a plan view of a one-piece blank from which the carton is constructed;

FIG. 2 is a partial perspective view of an end of the carton sleeve formed from the blank of FIG. 1;

FIGS. 3, 4 and 6 are partial perspective views showing successive steps in the closing of an end of the carton;

FIG. 5 is an enlarged, partial elevational view, partly cutaway to show the location of the gusset side flaps;

FIG. 7 is a fragmentary perspective view of the opening formed by the easy-open featurejand FIG. 8 is afragmentary perspective view showing the carton reclosed after being opened by the easy-open feature.

DETAILED DESCRIPTION OF THE INVENTION Referring first to FIG. 1, the carton is formed from a substantially rectangular blank, preferably of paperboard, suitably divided by cut and score lines into a conglomerate of connected panels, flaps and a tab. The paperboard used can be any of the types well known to those skilled in the art, e. g white patent coated newsback or solid bleached sulfate with or without a coating. The thickness of the paperboard generally ranges from about 0.020 to about 0.040 inch with a preferred range of from about 0.024 to about 0.026 inch for a carton with outside dimensions of 6 X 8% X 2 /4 inches. Elements of the carton are alternate side panels 11 and 13, front panel 10, back panel 12 and glue panel 20 which are separated from each other by score lines 28, 31, 35 and 34. The front flap 15, back flap 16, and gusset side flaps 17 and 18 are hinged totheir respective panels along score lines 33, 29, 32 and 27. Score line 33 is a cut-scoreline 23 for part of its length. Each side flap 17 and 18 is connected to the back flap 16 by score lines 38 and 39 and is divided into two parts, i.e., 17a and 17b and 18a and 18b, by hinge lines 24b and 24, respectively.

Hinge lines 24 and 24b run diagonally at approximately 45 to the hinge lines on each side flap to allow the two parts comprising each side flap 17 and 18 to fold together. Cut lines 24a and 240 are made along the diagonal hinge lines 24, 24b so that the parts 17a and will lie flat against parts 17b and 181:, respectively, when the side flaps 17 and 18 are folded, thus eliminating a potential avenue through which the packaged product could sift. Without the cuts 24a and 24c the resiliency of the paperboard tends to hold the side flap parts 17a, 17b and 18a, 18b apart. Preferably, cuts 240 and 24c extend from a location adjacent, e.g., about one-sixteenth to one-eighth inch from the intersection of the lines of articulation of the respective side flaps, to a point spaced therefrom by a distance equal to about one-half the length of the diagonal hinge line 24 or 24b. The remainder of the hinge lines 24 and 24b are scored so that each comprises a cut and scored line.

Tab 19 is attached and hinged to a part of side flap 18, i.e., 18b, by a cut-score line 25. Portions 19a and 19b of the tab 19 are separated by score line 26. A cut-score is a line of weakening comprising a score line which is provided with a cut partially through the material, approximately one-third to onehalf the material thickness, and is adapted to rupture prior to the rupture of the surrounding material when a separating force is applied. Other types of weakening could be used, e.g., perforations; however, cut-scores are preferable since such approach does not require complete penetration of the cartonboard.

The front flap includes a comer portion 15a defined by score line 22 and cut-score line 23. Back fiap 16 includes a comer portion 16a defined by score line 30 and the edges of the back flap. In the closed position score lines 22 and 30 are superposed and in direct alignment, thus the front flap comer portion 150 and the back flap comer portion 16a are generally coextensive, superposed, congruent, triangular-shaped comer portions. As will be more fully understood from subsequent description, this arrangement allows portion 15a and the underlying elements to rotate about score lines 22 and 30 after the uncut material of cut-score lines 23 and 25 has been severed.

Additional elements of the carton which form the closure at the other end are front flap 50, back flap 51, and side flaps 52 and 53. They are hinged to their respective panels along score lines 45, 43, 44 and 42. Both side flaps 52 and 53 are hinged and divided in the same manner as is side flap 17 previously described, i.e., they comprise side flap parts 52a, 52b, 53a and 53b. The side flaps 52 and 53 are also articulated from back flap 51 by score lines 40 and 41, respectively. The hinge lines 46b and 46 which traverse side flaps 52 and 53 are similar in construction and arrangement to hinge lines 24 and 24b, i.e., they have cuts along part of their length 466 and 46a, respectively.

The carton is formed by folding the blank shown in FIG. 1. Elements l0 and are folded about score line 35 so as to underlie panels 11 and 12, and panel 13 is folded about score line 28 to underlie glue panel 20. Panel 13 is then fastened to element 20 by any suitable means, preferably an adhesive. The packager receives the carton from the carton manufacturer in this collapsed tubular form. The packager will then set up, fill and seal the carton. FIG. 2 shows a perspective of the upper end of the carton after it has been formed by squaring the glued blank previously described.

Now referring to FIG. 3, the first step in the method of closing this carton is the simultaneous outward folding of side flaps l7 and 18, inward folding of back flap 16, and, if desired, outward folding of front flap 15. This simultaneous folding is preferable because all surfaces which are to receive adhesive 54 are aligned in virtually one plane during this step and front flap 15 is removed from the area of operation so an adhesive applying operation can be performed without interference. The top surface of back flap 16, the top surface of side flap portions 17b and 18a and the surface of tab 19 which originally faced inwardly are all essentially coplanar, and adhesive application in a single plane is simpler than adhesive application in several planes. The adhesive 54 can be applied by any of several methods well known to those skilled in the art, for example, rolling, spraying or extruding. Glue can be applied in a defined pattern such that a continuous strip down the center of the back fiap does not receive adhesive. This allows folding the flaps with fixed rails and moving tuckers without suffering an adhesive buildup on the folding mechanism.

Back flap 16 is then raised, tab 19 is folded out and down along cut-score line until it is folded back on side flap part 18b. Side flap parts 17a, 17b, 18a and 18b are tucked inwardly before back flap 16 is again folded down to close the carton. In FIG. 4 tab 19 has been folded down, side flaps l7 and 18 have been deflected inwardly, and back flap 16 has been started downwardly.

FIG. 6 shows the closure completed wherein the adhesivebearing surfaces of the side flaps 17 and 18 and the tab 19 adhere to the surfaces contacting them. The initially outward surfaces of side flap parts 17a, 17b are bonded together, and the initially outward surface of side flap part 18a is bonded to the inward surface of tab portion 19a and part of the outward surface of 18b. These bonds provide a siftproof seal along the top edges of panels 11 and 13. In this connection, the hole which could exist at the intersection of edge 36 of the tab portion 19a and edge 37 of side flap part 1821 is sealed by the interaction of the elements during closure. Edge 36 wipes the adhesive-coated outside surface of side flap part 18a and accumulates adhesive along its length. This interaction can be visualized from FIG. 4. The accumulated adhesive bonds the entire edge 36 between side fiap parts 18a and 18b and also fills any potential hole at the intersection of edges 36 and 37, thus preventing sifting.

With back flap 16 in its closed position, front flap 15 is rotated inwardly about score line.33 to its closed position, i.e., superposed on back flap 16. A bond develops between the adhesive-coated top of back flap l6 and the bottom surface of front flap 15.

The cutaways in FIG. 5 show the positions normally assumed by the inwardly folded side flaps 17 and 18. Side flap parts 18a, 18b and the tab part 19a therebetween assume a position immediately beneath back flap 16, while side flap parts 17a, 17!; go to a position approximately equidistant back flap 16 and the side panel 11 so that it lies at an angle of about 45 with the horizontal. Such positions are not critical in any respect and although the reason for the difference in the attitudes of these parts is not fully understood, it is believed that each side flap takes the position it does because the lines of articulation on side flap 18 are of unequal strength while the lines of articulation for side flap 17 are of equal strength. When folded innermost, the gusset side fiaps exert a springback force on the major flap to which they are attached, i.e., back flap 16. This springback force ensures almost full contact between the adjacent surfaces of the overlying major flaps, i.e., back flap 16 and front flap 15, thus enhancing the cartons sealability. The springback force also helps form excellent bonds between the gusset side flap parts. This design gives much protection against sifting, especially at high cartoning speeds.

Tab portion 19b is folded upwardly about score line 26 until it lies on top of front flap 15, as shown in FIG. 6. The inside surface of tab 19 is adhesive-bearing, therefore a bond develops between the inside surface of 19b and the outside surface of front flap 15. Pressure should be applied to the folded elements of the closure until all adhesive has had time to set. An adhesive release ink 55, as is well known to those skilled in the art, is printed on the portion of the front flap underlying the folded-over tab portion 19b to promote easy lifting of tab portion 19b when the consumer desires to open the package.

A mechanical seal is formed by the edges of back flap 16 and side flap parts 17a, 17b, 18a and 18b which come in contact with the inside of front panel 10. For best results, these edges are forced in contact with the front panel 10, by urging the front flap 15 as far toward the back panel 12 as is possible while the adhesive is setting up, as can be visualized from FIG. 4. Thus with solid adhesive lines between side flap part 18a and tab portion 19a, side flap parts 17a and 17b, and back and front flaps 16 and 15, and a bead of adhesive sealing any potential leak at the intersection of edges 36 and 37, the only location whereat a leak can occur is at one of two corners. These corners are at the intersection of score line 27 with cutscore line 23 and the intersection of score line 32 with score line 33. However, a tight mechanical seal exists at each of these two comers due to close carton design and the multiple paperboard thicknesses which can be bound tightly. Therefore the carton is virtually siftproof.

The adhering and sealing of the various elements of the carton construction may be achieved by using any suitable sealing or adhesive means. As used herein, adhesive is intended to convey the concept of any of the means well known to those skilled in the art' used to bond two paperboard surfaces together, including hot melt adhesives, heat sealing coatings, adhesive tapes and the like. For economy, one of the preferred bonding agents is glue, especially water-base glues of which dextrin, polyvinyl acetate, and polyvinyl alcohol are generic examples. A commercial brand of a polyvinyl acetate which has been used successfully is available commercially from Findley Adhesives, Inc. of Milwaukee, Wis., under the code designation Findley Adhesive Number 4751-358.

The bottom closure is formed by using the same general folding and adhesive application sequence as was described above. Back flap 51, side flaps 52 and 53, and front flap 50 are simultaneously folded; back flap 51 inwardly, side flaps 52 and 53 outwardly, and front flap 50 outwardly. Adhesive is applied to the virtually coplanar surface formed by back flap 51 and side flap parts 53a and 52b. Then back flap 51 is raised, side flaps 52 and 53 are folded inwardly, back flap 51 is folded inwardly, and front flap 50 is folded inwardly. Thus side flap parts 520 and 52b are superposed as are side flap parts 53a and 53b. Side flap parts 52a, 52b, 53a and 53b lie inside back flap 51, and front flap 50 lies outside back flap 51. Three adhesive bonds are formed, i.e., between the superposed side flap parts 52a and 52b, between side flap parts 53a and 53b, and between the inward surface of front flap 50 and the outward surface of back flap 51. This configuration offers reliably formed siftproof closure but no easy-open feature.

FIG. 7 shows the carton after being opened by using the easy-open feature, with the gusset side flap part 18b folded outwardly. The tab portion 19b is pried loose from the front flap l5 and pulled up and back in the direction of a line which would approximately bisect the angle formed by score line 27 and cut-score line 23. The object of this pulling is to separate the corner portion 15a of the top flap 15 from the adjacent front panel 10 along cut-score line 23 and to separate tab portion 19a from side flap part 18b along the cut-score line 25. This action rotates the assembly consisting of front flap comer portion a and the underlying elements about superposed score lines 22 and 30, and results in the formation of a triangular-shaped pouring opening.

After each partial use of the product the carton can be reclosed, as shown in FIG. 8. Reclosure is accomplished by folding gusset side flap part 18b inwardly and rotating the opened portion of the end closure, i.e., front flap corner portion 15a and the underlying components, downwardly about superposed score lines 22 and 30. Then the periphery of front flap corner portion 15a must be fitted within the confines of the upper edges of side panel 13 and front panel 10 with side flap part 18b folded down inside side panel 13 and the thickness of side flap part 18b between side panel 13 and the adjacent edge of the front flap corner portion 15a. This reclosing is sufficiently tight to exclude foreign matter from the package and also to prevent wholesale loss of the product should the consumer have the misadventure of inadvertently tipping the carton. This opening and reclosing can normally be performed as often as required until the product is exhausted.

The same general end closure design and folding and adhesive application sequence can be used when the abovedescribed easy-opening feature is not desired on the top closure. For example, in this case the top closure would be designed and closed as described in connection with the bottom end of the carton.

Although only certain modifications of preferred forms of this invention have been shown and described, it is clear that many others could also be made without departing from the spirit of the invention. The terms used in describing the invention are used in their descriptive sense and not as terms of limitation, it being intended that all equivalents thereof be included within the scope of the appended claims.

What is claimed is:

1. In a seal-end type carton having front and back panels and alternating side panels forming a tubular body of rectangular cross section and an adhesively sealed top closure formed by a front flap, a back flap, and two gusset side flaps, each of said flaps being joined to the correspondingly identified panel and articulated thereto, the gusset side flaps articulated also to said back flap and free of attachment to the front flap, one gusset side flap at each end thereof, each gusset side flap being traversed by a hinge line at about 45 to the side flap articulation lines and passing through their juncture, each gusset side flap thereby being divided into two parts, an improvement comprising:

each gusset side flap being folded inwardly and one said part being superposed over the other part, the adjacent faces of said parts being bonded together by adhesive means to establish a siftproof seal therebetween, said back flap immediately overlying said inwardly folded side flaps, and said front flap overlying said back flap and adhesively united thereto. 2. The carton of claim 1 having an easy-open reclosable feature which comprises:

a comer portion of said front flap, defined by a diagonal score line extending from a distal corner thereof to a point on the line of articulation separating the front flap from the front panel,

said last-mentioned line of articulation comprising a line of weakening along the portion thereof adjoining said comer portion,

a corner portion of said back flap being formed by a diagonal score line extending across said back flap, the diagonal score line on the back flap underlying and being in direct alignment with the diagonal score line on said front flap, whereby a pair of generally coextensive, superposed, congruent triangular-shaped corner portions of the back and front flap result,

a tab being attached to the gusset side flap directly underlying said corner portions along a tab articulation line at the distal edge of the gusset side flap part which is articulated from the side panel,

said tab articulation line comprising a line of weakening,

and

said tab being folded along said tab articulation line so as to lie on the top of the gusset side flap part to which it is attached, whereby said tab lies between said parts of the gusset side flap and extends outwardly beyond the adjacent side panel to form a gripping tab,

so that a pull on the gripping tab will sever the corner portion of said front flap from the front panel along the line of weakening therebetween, sever the gripping tab from the gusset side flap along the line of weakening therebetween, and fold the superposed corner portions along their diagonal score lines to form an opening in the end of the carton.

3. The carton of claim 2 wherein each said hinge line comprises a cut which extends for about one-half the length of the hinge line, said cut originating at a location adjacent the intersection of the lines of articulation of the gusset side flap, said cut allowing the superposed parts of each gusset side flap to fold substantially flat against each other.

4. The carton of claim 1 wherein each said hinge line comprises a out which extends for about one-half the length of the hinge line, said cut originating at a location adjacent the intersection of the lines of articulation of the gusset side flap, said cut allowing the superposed parts of each gusset side flap to fold substantially flat against each other. 

1. In a seal-end type carton having front and back panels and alternating side panels forming a tubular body of rectangular cross section and an adhesively sealed top closure formed by a front flap, a back flap, and two gusset side flaps, each of said flaps being joined to the correspondingly identified panel and articulated thereto, the gusset side flaps articulated also to said back flap and free of attachment to the front flap, one gusset side flap at each end thereof, each gusset side flap being traversed by a hinge line at about 45* to the side flap articulation lines and passing through their juncture, each gusset side flap thereby being divided into two parts, an improvement comprising: each gusset side flap being folded inwardly and one said part being superposed over the other part, the adjacent faces of said parts being bonded together by adhesive means to establish a siftproof seal therebetween, said back flap immediately overlying said inwardly folded side flaps, and said front flap overlying said back flap and adhesively united thereto.
 2. The carton of claim 1 having an easy-open reclosable feature which comprises: a corner portion of said front flap, defined by a diagonal score line extending from a distal corner thereof to a point on the line of articulation separating the front flap from the front panel, said last-mentioned line of articulation comprising a line of weakening along the portion thereof adjoining said corner portion, a corner portion of said back flap being formed by a diagonal score line extending across said back flap, the diagonal score line on the back flap underlying and being in direct alignment with the diagonal score line on said front flap, whereby a pair of generally coextensive, superposed, congruent triangular-shaped corner portions of the back and front flap result, a tab being attached to the gusset side flap directly underlying said corner portions along a tab articulation line at the distal edge of the gusset side flap part which is articulated from the side panel, said tab articulation line comprising a line of Weakening, and said tab being folded along said tab articulation line so as to lie on the top of the gusset side flap part to which it is attached, whereby said tab lies between said parts of the gusset side flap and extends outwardly beyond the adjacent side panel to form a gripping tab, so that a pull on the gripping tab will sever the corner portion of said front flap from the front panel along the line of weakening therebetween, sever the gripping tab from the gusset side flap along the line of weakening therebetween, and fold the superposed corner portions along their diagonal score lines to form an opening in the end of the carton.
 3. The carton of claim 2 wherein each said hinge line comprises a cut which extends for about one-half the length of the hinge line, said cut originating at a location adjacent the intersection of the lines of articulation of the gusset side flap, said cut allowing the superposed parts of each gusset side flap to fold substantially flat against each other.
 4. The carton of claim 1 wherein each said hinge line comprises a cut which extends for about one-half the length of the hinge line, said cut originating at a location adjacent the intersection of the lines of articulation of the gusset side flap, said cut allowing the superposed parts of each gusset side flap to fold substantially flat against each other. 